I'm trying to cluster a Xen VM using NCS and OCFS2. On the SAN device (/dev/dm-2 for example) there is already a small SBD partition because having installed the NCS components and creating a new cluster requires it.

However, I seem to be unable to mkfs.ocfs2 on the remaining free space. mkfs.ocfs2 -L label /dev/dm-2 won't let me create the file system because the SBD partition is already there. EVMSGUI doesn't show me that device at all. I also tried the various other ways of referring to the device in /dev/mapper and /dev/disk/by...

I'm wondering if I'm stuck and need to move the SBD somewhere else so that mkfs.ocfs2 can just create the fs on the whole device. But I'd rather be able to create the fs on the remaining free space.

Thanks for any advice.